Marginal food security harms children’s health and development. Research from Children’s HealthWatch and others shows that children in marginally food-secure households are at greater risk for health problems, developmental delay, and impaired school performance than children in food-secure households. These findings argue for child nutrition programs that reach the broadest spectrum of children whose families may be struggling, even at the margins, to put enough nutritious food on the table. They also strongly suggest that a national discussion is needed around the terminology used to classify levels of access to adequate food and nutrition.